Tsunamis - the catastrophic event

Dr Dave TappinBritish Geological Survey

In the Wolfson Suite, Ground
Floor
Edinburgh University Library
George Square, Edinburgh
On Thursday 17th November 2005, at 7 pm

Before December 26th 2004, for many the term 'tsunami' would
have been a mystery. All that changed when the Boxing Day
catastrophic tsunami, almost Biblical in its impact, devastated
the coasts of the Indian Ocean. The scale of the disaster, with
over 200,000 lives lost and uncounted numbers of people made
homeless would have made a massive international impact. However,
although the great majority of those affected lived in local
communities, the presence of foreign tourists resulted in a more
immediate awareness of the event to those outside the region.
Many people living in Britain and other European countries knew
of friends and/or relatives affected. Unusually, and mainly
because of the presence of tourists, there was an enormous volume
of visual images acquired. It raised levels of awareness and
concerns, not the least of which was that it might happen here in
Britain.

Scientifically, there is no doubt that the new information
available on the earthquake rupture mechanism and the resulting
tsunami has increased our knowledge of how these Earth processes
take place. This is normal. Our understanding of the massive
internal Earth forces that dominate our planet and control
earthquakes, volcanic activity and tsunamis is incomplete.
Extreme events are fortunately rare, often operating over
timescales that defy our oral and written histories so that we
have to fall back on indirect (geological) methods of
understanding how the Earth works. However, they can be utilised
to increase our understanding of Earth natural processes that can
be used downstream to develop our understanding of hazard and
risk. For that is the eventual objective of our research.

This talk focuses on the causes of tsunamis and presents on
the various different source mechanisms and impacts. It places
into context the recent Indian Ocean catastrophe and addresses
its causes. Mainly based on personal research it also discusses
previous tsunami case studies that have advanced our
understanding of these events. The threat to the UK is briefly
explored and whether our safety is more apparent than real.

Dave Tappin has worked for the
British Geological Survey for over 30 years, mainly in the fields
of marine and hydrocarbon geology both in the UK and also
extensively overseas. He has been researching tsunamis since 1998
when he was invited to lead the marine surveys into the cause of
the 17th July tsunami in Papua New Guinea, that claimed the lives
of over 2,000 people. Since this time Dave has been working on
tsunamis in Turkey, Hawaii and Bermuda, most recently taking part
in two marine expeditions investigating the cause of the Indian
Ocean event of 2004.